Evaluation of Genetic Parameters and Comparison of Stress Tolerance Traits in Different Strains of ILitopenaeus vannamei/I

The Litopenaeus vannamei shrimp is of paramount economic importance and has risen to prominence as a leading species in global aquaculture. Within its natural settings, Litopenaeus vannamei is subjected to a variety of environmental stressors that could negatively impact its survival, growth, and reproductive success. This study was designed to create specific lineages of Litopenaeus vannamei populations for resilience evaluation under stress conditions such as ammonia-N, pH, and salinity. Utilizing an exhaustive animal model that incorporates both genders, we performed a genetic parameter analysis to assess the heritability of stress tolerance traits in Litopenaeus vannamei. Concurrently, correlations among these traits were examined. Our findings lay solid theoretical groundwork for the selective breeding of Litopenaeus vannamei, providing valuable insights into enhancing varieties and improving economic yields. Furthermore, this research effort plays a crucial role in advancing the health and sustainable development of the aquaculture industry. Litopenaeus vannamei stands out globally in aquaculture for its fast growth, broad salt tolerance, disease resistance, and high protein levels. Selective breeding requires the precise estimation of the variance components and genetic parameters for important traits. This study formed lineages from 20 full sibling families of L. vannamei, with progenitors from Thailand and the USA. We then assessed the genetic resilience traits of juvenile shrimp from these families to high ammonia-N, high pH, and low salinity by performing a 96 h acute toxicity test. Mortality rates for the families under 96 h exposure to high ammonia-N, high pH, and low salinity were 19.52–92.22%, 23.33–92.22%, and 19.33–80.00%, respectively, showing significant variance in stress tolerance among families (p < 0.05). Survival heritability estimates, using threshold male and female models, were 0.44 ± 0.12 in high ammonia-N, 0.41 ± 0.12 in high pH, and 0.27 ± 0.08 in low salinity, respectively. Genetic correlations between growth and stress resistance traits varied from 0.0137 ± 0.2406 to 0.8327 ± 0.0781, and phenotypic correlations ranged from 0.0019 ± 0.0590 to 0.6959 ± 0.0107, indicating a low-to-high positive correlation significant at (p < 0.05). It was found that the survival rate of families No. 2 and No. 9 was higher under high ammonia-N and high pH stresses, while the survival rate of family No. 10 was higher under low salinity stress af